<!DOCTYPE html>
<html>
	<head>
		<meta charset="utf-8">
		<title></title>
	</head>
	<body>
		<button id="button">按钮1</button>
		<button class="button">按钮2</button>
		<button name="button">按钮3</button>
		<button>按钮4</button>
		<button type="button">按钮5</button>
		<button>按钮6</button>
		
		<script type="text/javascript">
			var btn1=document.getElementById("button");
			console.log(btn1);
			var btn2=document.getElementsByClassName("button")[0];
			console.log(btn2);
			var btn3=document.getElementsByName("button")[0];
			console.log(btn3);
			var btn4 = document.getElementsByTagName('button')[3]
			console.log(btn4);
			var btn5 = document.querySelector('[type]')
			console.log(btn5);
			var btns = document.querySelectorAll('button+button')
			console.log(btn6[4])
		</script>
	</body>
</html>
